/*
 * QEMU live migration
 *
 * Copyright IBM, Corp. 2008
 *
 * Authors:
 *  Anthony Liguori   <aliguori@us.ibm.com>
 *
 * This work is licensed under the terms of the GNU GPL, version 2.  See
 * the COPYING file in the top-level directory.
 *
 */

#include "qemu-common.h"
#include "migration.h"
#include "console.h"
#include "buffered_file.h"
#include "sysemu.h"
#include "block.h"
#include "qemu_socket.h"
#include "hw/hw.h"

#include <sys/time.h>

#define DEBUG_MIGRATION

#ifdef DEBUG_MIGRATION
#define dprintf(fmt, ...) \
    do { printf("migration: " fmt, ## __VA_ARGS__); } while (0)
#else
#define dprintf(fmt, ...) \
    do { } while (0)
#endif

/* Gigantea */
static struct timeval mig_start_tp, mig_end_tp;
static struct timeval wmem_trans_end;

static float get_mig_duration()
{
    float timeuse;
    timeuse = 1000000 * (mig_end_tp.tv_sec - mig_start_tp.tv_sec) + 
        mig_end_tp.tv_usec - mig_start_tp.tv_usec;
    timeuse /= 1000000;

    return timeuse;
}

static float get_wmem_duration()
{
    float timeuse;
    timeuse = 1000000 * (wmem_trans_end.tv_sec - mig_start_tp.tv_sec) +
        wmem_trans_end.tv_usec - mig_start_tp.tv_usec;
    timeuse /= 1000000;

    return timeuse;
}


/* END Gigantea */


/* Migration speed throttling */
static uint32_t max_throttle = (32 << 20);

static MigrationState *current_migration;

void qemu_start_incoming_migration(const char *uri)
{
    const char *p;

    if (strstart(uri, "tcp:", &p))
        tcp_start_incoming_migration(p);
#if !defined(WIN32)
    else if (strstart(uri, "exec:", &p))
        exec_start_incoming_migration(p);
#endif
    else
        fprintf(stderr, "unknown migration protocol: %s\n", uri);
}

void do_migrate(int detach, const char *uri)
{
    MigrationState *s = NULL;
    const char *p;

    gettimeofday(&mig_start_tp, NULL);
    //total_transferred_pages = demanding_pages = dirty_pages = 0;

    if (strstart(uri, "tcp:", &p))
        s = tcp_start_outgoing_migration(p, max_throttle, detach);
#if !defined(WIN32)
    else if (strstart(uri, "exec:", &p))
        s = exec_start_outgoing_migration(p, max_throttle, detach);
#endif
    else
        term_printf("unknown migration protocol: %s\n", uri);

    if (s == NULL)
        term_printf("migration failed\n");
    else {
        if (current_migration)
            current_migration->release(current_migration);

        current_migration = s;
    }
}

void do_migrate_cancel(void)
{
    MigrationState *s = current_migration;

    if (s)
        s->cancel(s);
}

void do_migrate_set_speed(const char *value)
{
    double d;
    char *ptr;

    d = strtod(value, &ptr);
    switch (*ptr) {
    case 'G': case 'g':
        d *= 1024;
    case 'M': case 'm':
        d *= 1024;
    case 'K': case 'k':
        d *= 1024;
    default:
        break;
    }

    max_throttle = (uint32_t)d;
}

void do_info_migrate(void)
{
    MigrationState *s = current_migration;
    
    if (s) {
        term_printf("Migration status: ");
        switch (s->get_status(s)) {
        case MIG_STATE_ACTIVE:
            term_printf("active\n");
            break;
        case MIG_STATE_COMPLETED:
            term_printf("completed\n");
            break;
        case MIG_STATE_ERROR:
            term_printf("failed\n");
            break;
        case MIG_STATE_CANCELLED:
            term_printf("cancelled\n");
            break;
        }
    }
}

/* shared migration helpers */

void migrate_fd_error(FdMigrationState *s)
{
    dprintf("setting error state\n");
    s->state = MIG_STATE_ERROR;
    migrate_fd_cleanup(s);
}

void migrate_fd_cleanup(FdMigrationState *s)
{
    qemu_set_fd_handler2(s->fd, NULL, NULL, NULL, NULL);

    if (s->file) {
        dprintf("closing file\n");
        qemu_fclose(s->file);
    }

    if (s->fd != -1)
        close(s->fd);

    /* Don't resume monitor until we've flushed all of the buffers */
    if (s->detach == 2) {
        monitor_resume();
        s->detach = 0;
    }

    s->fd = -1;
}

void migrate_fd_put_notify(void *opaque)
{
    FdMigrationState *s = opaque;

    qemu_set_fd_handler2(s->fd, NULL, NULL, NULL, NULL);
    qemu_file_put_notify(s->file);
}

ssize_t migrate_fd_put_buffer(void *opaque, const void *data, size_t size)
{
    FdMigrationState *s = opaque;
    ssize_t ret;

    do {
        ret = s->write(s, data, size);
    } while (ret == -1 && ((s->get_error(s)) == EINTR || (s->get_error(s)) == EWOULDBLOCK));

    if (ret == -1) {
        ret = -(s->get_error(s));
        dprintf("socket ERRNO: %zd\n", ret);
    }

    if (ret == -EAGAIN)
        qemu_set_fd_handler2(s->fd, NULL, NULL, migrate_fd_put_notify, s);
    
    return ret;
}

/* Gigantea */
void migrate_fd_connect(FdMigrationState *s)
{
    int ret;

    s->file = qemu_fopen_ops_buffered(s,
                                      s->bandwidth_limit,
                                      migrate_fd_put_buffer,
                                      /* migrate_fd_put_ready, */
                                      hybrid_migrate_fd_put_ready,
                                      migrate_fd_wait_for_unfreeze,
                                      migrate_fd_close);
    
    dprintf("begining savevm\n");
    ret = qemu_savevm_state_begin(s->file);

    gettimeofday(&wmem_trans_end, NULL);

    if (ret < 0) {
        dprintf("failed, %d\n", ret);
        migrate_fd_error(s);
        return;
    }

    // migrate_fd_put_ready(s);
    hybrid_migrate_fd_put_ready(s);

}

void hybrid_migrate_fd_put_ready(void *opaque)
{
    FdMigrationState *s = opaque;
    int err;
    kvm_mig_stat *stat;
    
    if (s->state != MIG_STATE_ACTIVE) {
        dprintf("put_ready returning because of non-active state\n");
        return;
    }

    if (qemu_savevm_ram_bitmap_ready(s->file)) {
        vm_stop(0);

        bdrv_flush_all();
        qemu_savevm_state_complete(s->file);

        qemu_fflush_all(s->file);
        
        /* 
         * Entering demanding page, and return 0 when
         * all the dirty pages has been synced.
         * */
        err = hybrid_migrate_fpage_req_waiting(s);

        if (!err) {
            gettimeofday(&mig_end_tp, NULL);
            s->state = MIG_STATE_COMPLETED;
            migrate_fd_cleanup(s);

            fprintf(stderr, "Whole mem transferring time: %f\n", get_wmem_duration());

            fprintf(stderr, "Total migration time: %f\n", get_mig_duration());
            
            stat = get_migration_stat();
            fprintf(stderr, "[total_pages] = %lu, [dirty_pages] = %lu, [page_demanding] = %lu\n",
                    stat->total_transferred_pages, stat->dirty_pages, stat->demanding_pages);
        } else if (err < 0){
            fprintf(stderr, "Hybrid migration, FT page pushing failed! ERROR: %m\n", err);
            exit(1);
        } else {
            fprintf(stderr, "Hybrid mig., receiving FT page request failed!\n");
            exit(1);

        }
    }
}
/* END Gigantea */

void migrate_fd_put_ready(void *opaque)
{
    FdMigrationState *s = opaque;

    if (s->state != MIG_STATE_ACTIVE) {
        dprintf("put_ready returning because of non-active state\n");
        return;
    }

    dprintf("iterate\n");
    if (qemu_savevm_state_iterate(s->file) == 1) {
        dprintf("done iterating\n");
        vm_stop(0);

        bdrv_flush_all();
        qemu_savevm_state_complete(s->file);
        s->state = MIG_STATE_COMPLETED;
        migrate_fd_cleanup(s);
    }
}

int migrate_fd_get_status(MigrationState *mig_state)
{
    FdMigrationState *s = migrate_to_fms(mig_state);
    return s->state;
}

void migrate_fd_cancel(MigrationState *mig_state)
{
    FdMigrationState *s = migrate_to_fms(mig_state);

    if (s->state != MIG_STATE_ACTIVE)
        return;

    dprintf("cancelling migration\n");

    s->state = MIG_STATE_CANCELLED;

    migrate_fd_cleanup(s);
}

void migrate_fd_release(MigrationState *mig_state)
{
    FdMigrationState *s = migrate_to_fms(mig_state);

    dprintf("releasing state\n");
   
    if (s->state == MIG_STATE_ACTIVE) {
        s->state = MIG_STATE_CANCELLED;
        migrate_fd_cleanup(s);
    }
    free(s);
}

void migrate_fd_wait_for_unfreeze(void *opaque)
{
    FdMigrationState *s = opaque;
    int ret;

    dprintf("wait for unfreeze\n");
    if (s->state != MIG_STATE_ACTIVE)
        return;

    do {
        fd_set wfds;

        FD_ZERO(&wfds);
        FD_SET(s->fd, &wfds);

        ret = select(s->fd + 1, NULL, &wfds, NULL, NULL);
    } while (ret == -1 && (s->get_error(s)) == EINTR);
}

int migrate_fd_close(void *opaque)
{
    FdMigrationState *s = opaque;
    return s->close(s);
}
